The development of a sensitive assay for the detection of Thomsen- Friederich antigen in human body fluids is proposed. Highly specific peptides were selected through phage display libraries to target this carbohydrate antigen associated with various human tumors (KD of peptide- antigen binding up to 5 nM). To facilitate the immobilization of the above peptides on solid support without loss of affinity, reduce non-specific interactions in the assay and eliminate blocking step, a new approach in modification of low sorption supports was developed using photoactivatable carbene-generating crosslinkers. Based on this immobilized affinity peptides setup three different reporting systems (ELISA-type sandwich, fluorescence quencher competition and enzyme conjugate competition) will be tested and optimized for the highest T-antigen signal-to-background ratio. The resulting dipstick-type test kit is expected to combine high performance with simplicity of one-step procedure. We believe this development will provide an inexpensive and reliable method of non-invasive screening and monitoring of broad patient groups for earlier stage cancer detection. The process is easily adjustable for automation. PROPOSED COMMERCIAL APPLICATION: The diagnostics of cancers at early stages is the major factor in patient survival prognosis that makes regular screening of groups with higher risk of cancer a vital necessity. The need for affordable and reliable assays for cancer screening is very high and there is a large market potential for the proposed product. The proposed technique is expected to provide an inexpensive, rapid, sensitive and reliable alternative to the currently available assays. It will also find application in laboratory research of cancer glycobiology.